Extraction of copper from ores



Y es

Patented Mar; e,Y 1932v EDWARD Eisma/Auna, an., on-'Los ANGELES; canrronm, Assmann#orforen-:smartA e f Y To gonannnsvagimmma, formes 'f' v ANGELES, v oamnonma EXTRACTION or corran rnonr'onns 1" No Drawing. f.

Heretofore, it-has vbeen impossible to prof- Y itably work certain classeso copper silicatecarbonate-oxide ores economically owing to 15` the Waste of expensive solvent `reagents'due to the presence of acid vconsumingconstituents other than the copper. In the present inventiomhowever, two stages are employed.

In the irst stagerthe carbonate of lime and "'20 other valueless acid consuming constituents are neutralized together with vpart of' the copper by a relatively cheap acid: and aseo-1 ond acid solvent is then added which needy only dissolve they remainder' of the copper content,which is chieflyy in the form of silicate. Y f

Numerous tests Y present time,

have beenimade up to the an extraction of from 90 to 95% on ore of c ithe above ydescribed nature. Y Asan example an ore of the following content vwas treated:`

1 i y Percent yCopper f l 8.60

35 Calcium carbonate 2.40 The copper was carried as silicatesii- 40 Y n as carbonat'es; 60

. Y Treating the above ore by the present process a recoveryor'V 93.8% lwas obtained with a very low acid consumption.,Y

' 50 suit-able to the particular `orebeingtreated.y

Application lileflfirnney 16,

- 'to the :ground substantiallyallof which vshow n Y Varate and distinct;V stepsitis desiredto beun- The acids employed int-he process aresulv 1930; Vseria mi. 461,634-

Vhas been :foundhighly satisfactory.V

` Ina'class of ore as mentiOIIGCl'V-abovef() mesh .2j First acid reagent. From Sto 10% by weight sulphuric' acidi (density 1.84"),

make an agitatable pulp.,A

' ,First agitation.

bring the particles into intimate-contact with thejreagent. fllhi's agitation is carried on second reagent is now slowly agitated -or f fromfl.)l to lGhours.

.6.,Thrd agitation. n weight of .the-,ore is now added to the -pulp 'The pulp j is, slow-ly agf Vtatedin anyV suitable aU'tat'i-ng mechanism to Approximately' 5% by' weight of hydrochloric .acid densityfll to is added ore with sufficient lWater to Water. equal to the I i andthe entire mass' isfagitated for an ad-dlk-l Y tion.

turned to Step on succeedingbatch. v

While the abovehas been described as sep-- derstood thatV the agitation `is `'continuous and .the .reagents VVand water added during this contin-nous agitation. 4 c

fThe copper is precipitated from the .solution with .scrap iron or mon precipitating xmethods and is :melted into bars inthe form if'cem'entcopper; Bars produced bythis method" show apurity of rom98 .to99%. 1'- f Y The Ysulphuric kacid because of its cheapness yand is always used ,rst andactstoineutralize .the lime and otherfacid-consmnng constituentsA of the ore and carries practicalby any of thecom- Y ly all ofthe carbonates of 'copper 'into'solution. This leaves thesilioates of copper thor- I' oughly cleaned Vand free fso that when-"theL hysie drochlorc ,acid is added, it, together with `the, I

remaining free snlphurcacid,

will be able to immediatey act Vupon the silicateso copper so as tofplace the latter yint,c'rsolutfiin.V

y The solution atterthe precipitation aofi-the these basic ferrie salts is also well known, y

hence the re-use or return of solutions to succeeding batches will tend to materially di minish the amount of the acids indicated in the above outline of the process.

i yWhile preferred formsr of the invention i have been described in some detail, together with the theories which it is believed to best explain its success, it is to be understood that the invention is not limited to the precise procedure described nor is depen-dent upon the accuracy of the theories which have been advanced. -On'the contrary, the invention is not to be regarded as limited except in so far as such limitations are included Within the terms yof the accompanying claims, in 'Whichvit is the intention to claim all novelty inherent in the invention as broadly as is permissible in view of the prior art. `1

Having thus described the invention what is claimed and desired secured by Letters Patent is: l

1. A process for the extraction of copper fromk a copper carbonate, silicate ore comprising: treating said ore with sulphuric acid, agitating said` treated ore until the carbonates are substantially dissolved, thence ores carrying calcium carbonate, copper carbonate, copper silicate and copper oxlde comprising: adding sulphuric acid to said ore; allowing ya sufficient time to elapse for the substantial solution of the calcium and copper carbonates; thence adding hydrochloric acid :for the dissolution of the remaining copper silicates and oxides.

In testimony whereof,y I affix my signature.

EDWARD 'EIsENHAUEa JR.

f ss n adding hydrochloric acid thereto; and further agitating said Ore, said sulphuric acid and said hydrochloric acid until the silicates are substantially dissolved. y

' 2L A process for the extraction of copper from carbonate, silicate ores comprising: irst treating said ore with sulphuric acid to'dissolve the carbonates, thence adding hydrochloric acid to the treated pulp to dissolve the silicates; drawing off the final acid solution; precipitating the copper therefrom with iron; returning the el'Huent acid solution from sai-d precipitation to fresh ore as a solvent for the carbonates.

v 3. A process for treating ores carrying copper both as carbonates and as silicates comprising: first dissolving they carbonates from said orevwith sulphuric acid; thence dissolvingtheremaining copper silicates with Y hydrochloric acid.

y 4; A process for treating ores carrying copperboth as carbonates and as silicates comprising: neutralizing the lime with sulphuric acid thence treating the residue with ydrochloric acid as n per silicates. f f Y 5. A process for recovering copper from a solvent for the copi 

